It wouldn't qualify as porneia. But it would probably be regarded as sexual uncleanness due to the homosexual inclinations underpinning the action.
To JWs it's not the same as an unmarried man and unmarried woman kissing. That can be regarded as somewhat legitimate if the man and woman are courting (even if it could often be seen as skirting the line of what they would consider as recommended behavior, depending on the nature of the kiss and the setting in which it was done).
But a homosexual kiss is never under any circumstances legitimate or excusable as it involves acting on sinful and unnatural desires, according to their teachings. Depending on the setting in which it was done, the elders might make a case for brazen conduct and DF you on that ground.